Pneumatic drill.



. 15 12 ml[ 1e PATENTED MAY 19, 1908. M. HARDSOGG.

PNEUMATIC DRILL.

APPLICATION FILED APR. 15, 1907.

MARTIN HARDSOGG, OF OTTUMWA, IOWA.

PNEUMATIC DRILL.

Specification of Letters Patent.

Patented May 19, 1908 Application flled April 15, 1907. Serial No. 868,3 88.

To all whom it may concern:

Be it known that LMARTIN HARDSOCG, a citizen of the United States, residing at Ottumwa, in the county of Wapello and State of Iowa, have invented certain new and useful Improvements in Pneumatic Drills, of which the following is a specification.

The present invention relates more particularly to the construction and arrangement of the hammer frame and the cross head carrying the operating tool, such as the bit or cutter of a pneumatic drill, so as to have the hammer frame coact with a conveyer or flight for removing the cuttings, dust and fine particles produced by the operation of the tool.

The objects of the invention are to improve the construction of the frame of a pneumatic hammer so as to enable air, or other medium under pressure, to act and operate the hammer, and to be rearwardly discharged for maintaining a perfect clearancein front of the hammer for each forward thrust or blow of the hammer; to construct a frame for a pneumatic hammer so as to provide a barrel,

with a chamber for the hammer and for the exterior formation to furnish a means for removing cuttings, dust and fine particles from in front of the tool head to construct a frame havin a central barrel with a hammer therein, and aving, circumferentiallyaround the barrel, oppositely running spiral flanges rearwardly extending from end to end of the barrel and furnishing op ositely running spiral pathways of travel or removin the cuttings, dust and fine particles pro need by the operationof the drill, or other tool, or instrument, from in front of the tool head; to construct the frame of a pneumatic hammer so as to provide a central straight barrel, with a chamber for the hammer and for the driven shank or stem of the tool head, and having, circumferentially around the barrel, oppositely running spiral flan es extendin from end to end of the barrel, each spira flange having a passage for admitting a1r,or other medium under 1pressure, to reciprocate the hammer, and eac spiral flange having a passage rearwardly extendin for discharging the air from'in front of the chamber, so as to leave a perfect clearance in the chamber in advance of the hammer; to construct a frame for a pneumatic hammer having a central straight barrel, with a hammer therein and a driven stem in advance of the hammer, and having, circumferentially around the barrel, oppositely running spiral flanges with a passage and port in each flange for admitting compressed air, or other medium under pressure, to the hammer chamber for'driving the hammer forward, and with a passage and port in each spiral flange and extending rearwardly for discharging air, or other medium under pressure, from in front of the hammer, so as to leave a perfect clearance in the chamber in advance of the hammer to provide aframe with a central chamber and having oppositely running spiral flanges on its exterlor and extending the length of the frame from end to end, each iral flange having a spiral passage for inucting fluid, and each spiral flange having a spiral passage for educting fluid rearwardly for discharging fluid at the rear of the frame and into a conduit or passage for final escape; to construct a frame for a pneumatic hammer having a central straight barrel to receive a driving hammer and driven stem, and having, circumferentially around the barrel, oppositely running spiral flanges, with an induction passage for fluid in each flan e and an eduction passage for fluid in each ange, and a closing plug for the end of the frame and a hammer chamber, the plug having an induction assage in communication with the induction passages of the spiral flanges and an'eduction passage in communication with the 'eduction passage of one of the spiral flanges; to furnish a frame consisting of a central barrel and oppositely running spiral flanges circumferentially around the barrel and extending from end to end of the frame, with an induction assage in each flange for admitting fluid to t e chamber of the barrel, and an induction passage in each spiral flange, both passa es rearwardly extending for educting fluid from the chamber of the barrel in front of the hammer, for the flanges to furnish a conveyer or flight for withdrawing cuttings, dust and fine particles from in front of the tool head, the conveyer or flight cooperating with a conveyer or flight on a rearwardly extending tube connected with the hammer frame; to furnish a conveyer or flight circumferential around a hammer frame, and a conveyer or flight circumferentially around a tube carrying the hammer frame for effecting a withdrawal of the cuttings, dust and'fine particles from in front of a tool head, without interference from fluid educt'ed from the hammer frame; to furnish a hammer frame having a central barrel, and having, circumferentlally around the barrel,

', oppositely running s iral flanges, each spiral I the frame, for the flanges to furnish a conveyer 0r flight for withdrawing the cuttings,

dust and line particles, and cooperating with a spiral flange having a longitudinal assage and circumferentially encircling a tu e carrying the hammer frame, so that the eduction passage of one flange discharges into the carrying tube, and the eduction passage of the companion flange discharges into the passage of the spiral flange around the carrying tube, to educt fluid from in front of the driving hammer without obstructing the withdrawal of the cuttings, dust and fine particles, by the 0 eration of the conveyer or flight formed by t e s iral flanges on the hammer frame and on the supporting tube; and to improve generally the construction, arrangement and operation of the frame and the correlated conveyers or flights entering into the formation of the drill as a whole.

The invention consists in the features of construction and combinations of parts hereinafterdescribed and claimed.

In the drawings Figure 1 is a full elevationof the hammer frame and supporting tube therefor, with oppositely running spiral flanges on the hammer frame and the spiral flange around the supporting tube constituting the conveyer flight for withdrawing the cuttings, dust and fine particles; Fig. 2 a sectional elevation of the pneumatic hammer and frame and the conveyer or flight, showing the construction for the frame as if the spiral flanges were unfolded in order to clearly illustrate the induction and eduction passages in the two spiral flanges, and with the supporting tube and the supply tube for fluid partly in section and broken away; Fig. 3 a cross section on line aa of Fig. 2; Fig. 4 a cross section on line bb of Fig. 2; and Fig. 5 across section of the closing lug, for the endof the barrel chamber and t e frame on the line cc of Fig. 2, looking in the direction of the arrow.

The drill shown has a head with a plurality of bits or cutters, but other forms of bits or cutters could be used, and other forms of tools or instruments than drills are capable of use with the frame and the conveyer or flight. The arrangement has, at each end of the drill head, an outer or end bit or cutter 1, with an intermediate bit. or cutter 2 and an intermediate bit or cutter 3, so that the head has a plurality of bits or cutters.

30, whic The head lis of a shape, as to length and width, to receive the bits or cutters; and, as shown, the head has a cross hole 5 so as to facilitate the removal, from the head, of the bit or cutter in line with the shank or' stem. The head has a shank or stem 6 to enter the chamber 7 of the barrel 8 of the frame, which shank or stem constitutes a driven shank or stem, and, as shown, the driven shank or stem has a slot 9 through which passes a key or bar 10 secured in the wall of the barrel,

and by which slot and bar the head has a limited end movement for operating the bits or cutters.

The frame has, circumferentially extending therearound, two spiral flanges 11, with the run of the spirals in opposite directions so as to furnish a double spiral pathway of travel around the barrel; and each spiral flange, at the forward end of the frame, has

a projection 12 forming a shoulder 13 against which the end of an encircling tube, when used, can rest. The chamber 7 terminates in a chamber 14 of a greater diameter incross section than the chamber 7; and from this chamber 14, on opposite sides, a port 15 leads. Each port 15 communicates with a longitudinal spiral passage 16 formed in each of the spiral flanges, with the passage 16 of one flange opening through the rear end of the flange and frame, and With the passage 16 of the other flange opening at its rear end into a lateral port 17, inwardly leading from the end of the passage, as shown in Fig. 2.

The barrel 8 has an 1nteri0r circumferential wall 18 located between the chamber 14 and a chamber 19, and from the chamber 19, on opposite sides, a port 20 leads. Eachport 20 is in communication with a longitudinal gipiral passage 21, formed in each spiral ge of the frame, and each spiral passage 21, at its rear or receiving end, has a port 22 inwardly leading therefrom. Each port 22 communicates with a common port or cross passage 23 with which a longitudinal passage 24 communicates, and the cross passage 23 and longitudinal passage 24 are formed in ahead 25, having a shoulder 26 and a neck 27, with anexterior screw thread on the head and the neck, for the neck to be entered into the end wall of the frame and barrel, as shown in Fig. 2, so that the passages 23 and 24, in the head and neck, furnish a conduit or passage for supplying compressed air, or other medium under pressure, to the spiral passages 21 of the frame. The head 25 and neck 27 have a wall or partition 28 separating the passages 23 and 24 from a cross passage or port 29 and a longitudinal passage opens to the rear end of a head 25, as shown in Fig. 2. The port 17 is in communication with the cross passage or port 29, so that fluid inducted from the chamber 14, on one side and forward of the acting end of the hammer, will flow through port 15 and as a whole.

passage 16, and by the ports 17 and 29 discharge into the passage, 30 and escape at the mouth or opening of said passage at the rear end of. the head, and the fluid inducted through the companion spiral passage 16 will escape at the mouth or opening of said passage at the rear end of the spiral flange and the frame, so that the educted fluid will escape at the rear of the hammer frame and the closing plug and will maintain a perfect clearance for the acting end of the hammer, and prevent back pressure from interfering with the strike or blow of the hammer in use.

The barrel has an interior circumferential wall 31, located between the chamber 19 and a chamber 32, which chamber is continued as a chamber or hole 33, .which receives the neck .37 of the closing plug,as shown in Fig. 2, so that the chamber of the barrel, as a whole, is closed at the outer or rear end by the plug, the shoulder26 of which abuts tightly against the rear end of the barrel, so as to form a joint against the escape of admitted fluid. The barrel has located in the chamber thereof, rearward of the shank or driven stem 6, a hammer having a driving end or head 34, continued as a body 35, guided and held between the circumferential wall 18 and terminating at its rear end in an enlarged portion or head 36, guided and held in the circumferential wall 31 and forming an abutment or end face 37 against which the compressed air, or other medium under pressure, admitted to the chamber 19 from the spiral passages 21, through the ports 20, acts to recede or force back the hammer, as a whole, into striking position. The body 35 of the hammer has a central passage 38 extending longitudinally therein, and o ening at its rear end through the head 36, from which passage 38 lateral ports or passages 39 lead through the head 36, so that when the hammer is receded communication is established with the chamber 32, admitting compressed air, or other mediumunder pressure, to the assage 38, for' the air, or other medium un er ressure, to act and thrust or drive forward t e hammer The passage 38, adjacent to its forward end, has leading therefrom lateral ports or passages 40 to furnish communication between the passage 38 and the chamber 14, for compressed air, or other medium under ressure to flow from the passage 38 through the ports 15, into the spiral passages 16 and be discharged on one side at therear end of the hammer frame and at the other side through the port 17 into the cross passage 29 and longitudinal passage 30, maintaining a clearance against back pressure for the acting end of the hammer.

The head or lug 25 has a screw threaded hole at the end of the longitudinal passage 24, which receives a tube 41 leading from'a source of compressed air, or'other medium 'ticles produced by the under pressure, for sup lying compressed air, or other medium un er ressure, to the passage .24, for the air, or ot ier medium under pressure, to enter the spiral passage 21 in each spiral flange through the ports 22, and be discharged through the ports 20 of the spiral flanges into the chamber 19 to act against the abutment or end face 37 of the hammer and force back or recede the hammer, as a whole, into its striking osition.

The supply tube 41 is encircled by a tube 42, the end of which is threaded onto the head 25, sothat the tube 42 su ports and carries the hammer frame with the hammer and the operating tool; and the 'su porting tube 42 has a circumferential spiral flange 43 therearound, which flange is hollow so as to furnish a passage 44'within the spiral flange.

The passage 30 discharges into the interior of the tube 42, and the passage 16 discharges into the passage 44, so that the educted fluid from one spiral flange 11 is discharged into the interior of the supporting tube 42, and the educted fluid from the other spiral passage 16 is discharged into the assage 44 of the s iral flange. 43, thereby eflectin a perfect discharge of the fluid from eacl i s passage 16, with an independent trave for each discharge;

The supporting tube 42,. with its spiral flange 43, forms a conveyer or flight to coact with the spiral flanges of the hammer frame,

iral.

for removing the cuttings, dust and fine parrill, or other tool or instrument, with the result that the removal of the cuttings, dust and fine particles from in front of the tool headis not interfered with by the educted fluid from the hammer chamber, as the cuttings, dust and fine articles have a pathway of travel rearwar y independent of the educted fluid, for the educted uid to furnish a perfect clearance for the driving end of the hammer, and for the withdrawn cuttings, dust and fine particles to furnish a perfect clearance for the operation of the bits or cutters, or other tool.

The parts are assembled by entering the shank or stem 6 in the chamber 7 of the barrel 8, and securing the shank or stem 6 and the head 4, with the bits or cutters thereon, against dropping out fromthe chamber, by means of the bar or key 10 entered into the wall of the barrel and passing through the slot 9 of the shank or stem. The hammer, as a whole, is entered into the chamber of the barrel rearward of the driven stem 6 of the head, and after the hammer is entered, the plugor head 25 is entered into the end of the frame and the barrel, so as to close the chamber of the hammer and have the port or passage 23 in communication with t e ports 22, as shown in Fig. 2. The su ply tube 41, and the supporting tube'42 wit its spiral flange 43, are connected respectively to the center the hammer.

and exterior of the closing'plug or head, com- )leting the connecting up of the parts, ready for the'operation of the drill.

In operation, the compressed air, or other medium under pressure, flows through the.

supply tube 41, into the passage 24, and through the cross port or passage 23, and the ports 22, enters both spiral passages 21 to discharge through the ports 20 into the chamber 19 and act against the abutment or end face 37 to force backor recede the hammer into striking or driving position. The hammer is receded a sufficientdistance to carry the abutment or end face 37 clear of the rear face of the wall 31, so that fluid can enter the 1 against the end of the passage 38 to overcome.

the pressure against the abutment or end face 37 and drive forward the hammer, as a whole, and in such driving forward of. the hammer the admitted 'fluid cannot escape from the passage 38 owing to the closing of the lateral passages or ports 40 with the passing of such passages or ports within the circumferential wall 18, by the recession or forcing back of The forward drive or thrust of the hammer causes its acting end or head 34 to contact'the end of the driven shank or stem 6 and drive forward the shank or stem and with it the head 4 and the bits or cutters, or other tool, carried by the head, for the bits or cutters, or other tool, to act and perform the cutting or drilling operation.

The forward throw or drive of the hammer, as a whole, closes the ports orpassages 39 by the wall 31, and opens the portsor passages 40 for communication between the passage 38 and the chamber 14, admittingfluid to the chamber 14 for the fluid to flow through the ports 15'and enter the spiral passage 16 on one side to discharge at the rear end of such passage into the spiral passage 44 of the spiral flange 43, for final discharge at the end of the flange, and for the educted fluid to enter the companion spiral passage 16 and discharge through the ports 17 and 29 into the passage 30 to flow through the interior of the supporting tube 42, for final discharge at the end of such tube. The compressed air, or other medium under pressure, discharged by the passages 16, from in front of the hammer, has a free passage rearward through the spiral passages 16 in each spiral flange, for final discharge through the interior of the supporting tube 42 and the assage 44 of the splral flange 43, leaving a c ear drive for the hammer at each succeeding operation.

The cuttings, dust and fine particles, produced by the cutting or boring operation, enter the spiral pathways furnished by the spiral flanges on the exterior of the hammer frame and are carried upward or rearward by such flanges and spira pathway to be caught by the conveyor or flight, formed by the spiral flange 43 on the supportin 'tube 42, and carried upward and rearwar to the discharge .end of the tube, so that the cuttings, dust and fine particles are removed or carried back as fast as reduced and cannot accumulate around t e bits or cutters, or other tool, and interfere with the operation of the drill, or other tool, thus maintaining a perfect clearance for the operation of the bits or cutters, or other tool.'

The frame of the present-invention, in connection with the hammer chamber and exterior spirals and the hammer and cross head having bitsor cutters, furnishes a drill by which the frame supplies the air, or other medium under pressure, to operate the hammer and discharges the compressed air, or other medium under pressure, from in front of the acting end of the hammer, so that the acting or forward end of the hammer has a perfect clearance against back pressure from the compressed air, or other medium under pressure, that would interfere with the blow struck by the hammer. The spiral flanges of the frame, in connection with the spiral flange of the supporting tube, furnishes a -conveyer or flight by means of which the cuttings, dust and fine particles will be carried away from the actin end of the drill, or other tool, as fast as pro(. uced, and so as not to interfere with the operation of the bits or cutters.

It will thus be seen that the frame oft-he resent invention, consisting of a straight barrel with exterior spiral flanges around the barrel, furnishes, by the passages in the flanges, a means for su plying compressed air, or other medium univ or pressure, to operate a hammer, and means for educting compressed air, or othermedium under pressure so as to prevent the creation of back pressure against the acting end of the hammer, and the spiral flanges furnish a means for initially drawing away or removing the cuttings, dust and fine particles produced by the bits or cutters, or other tool, for final removal or drawing away .by the conveyer or flight on the supporting tube, making such removal or drawing away of the cuttings, dust and fine particles positive, effectual and reliable, durmg the operation of the drill, or other tool, and giving an independent and separate athway of travel for the educted fluid and or the removal of the cuttings, dust and fine particles, so that the educted fluid will not interfere with the removal of the cuttings, dust and fine particles.

The frame of the present invention, with its straight barrel and exterior spiral flanges, and the conveyeror flight cooperating with the spiral flanges, is especially adapted for use in deep drilling or boring, as the spirals of the frame, in conjunction with the conveyer or flight, will operate to carry upward or rearward of the head carrying the tool, all the cuttings, dust and fine particles, and such carrying upward or rearward of all the cuttings, dust and fine particles is ositively performed by the spiral flanges and the conveyer or flight, and at the same time the framepermits compressed air, or other medium under pressure, to be inducted for operating the hammer, and to be educted for kee ing the acting end of'the hammer clear of melt pressure, and this Without in any manner interferin with the removal of the cuttings, dust and fine particles; and while the pneumatic hammer, with its exterior flanges, in connection with the conveyer or flight, is shown in conjunction with a tool head carrying drill bits or cutters, it is to be understood that the hammer, with its strai ht barrel and spiral exterior flanges for the flame, is intended for use, and can be used, with a tool head of other formation than the one shown, and for other purposes than dee drilling or boring.

What claim as new and desire to secure by Letters Patent is? 1. In a pneumatic drill, a hammer frame consisting of a straight central barrel with oppositely running s iral flanges encircling the barrel and extending from end to end of the barrel, the barrel having a central chamber divided into sections, one section to re ceive a driven stem and another section to receive a driving hammer, and each spiral flange having a spiral induction passage and a spiral eduction passage, with the eduction passage of one flange terminatin at the end of the flan e and frame, and t e eduction passage of t e other spiral flange terminating in a port laterally extending inwardly, substantially as described.

2. In a pneumatic drill, a hammer frame consisting of a straight central barrel with o positely running s iral flanges encircling t e barrel and exten ing from end to end of the barrel, the barrel having a central chamber divided into sections, one section to receive a driven stem and another section to receive a driving hammer, and each spiral flange having a spiral induction passage and a spiral eduction passage, with the eduction passage of one flange terminatin at the end of the'flan e and frame, and t e eduction passage of t e other spiral flange terminating in a port laterally extending inwardly, and a closing plug for the rear end of the frame and chamber of the barrel, the plug having an induction passage in communication with the induction passages of both spiral flanges, and an eduction passage in communication with the eduction passage of one spiral flange, substantially as described.

3. In a pneumatic drill, a haminer frame consisting of a straight central barrel with oppositely running s iral-flanges encircling the barrel and extending from end to end of the barrel, the barrel having a central chamber divided into sections, one section to receive a driven stem and another section to receive a driving hammer, and each spiral flange having a spiral induction assage and a spiral eduction passage, with t e eduction passage of one flan e terminatin at the end of the flan e and ame, and t e eduction passage of t e other spiral flange terminating 1n a port laterally extending inwardly, a closing plug for the rear end of the frame and chamber of the barrel, the plug havin an induction passage in communication W1th the induction passages of both spiral flanges, and an eduction passage in communication with the eduction passage of one spiral flange,-and a fluid supply tubeconnected with the closing plug and in communication with the induction assage of the plug, substantially as described.

4. In a pneumatic drill, a hammer fram consisting of a straight central barrel with o positel running spiral flanges encircling t e barre and extending from end to end of the barrel, the barrel having a central chamber divided into sections, one section to receive a driven stem and another section to receive a driving hammer, and each spiral flange having a spiralinduction assage and a splral eduction passage, with t e eduction passage of one flange terminatin at the end of the flan e and frame, and t e eduction passage of the other spiral flange terminating in a port laterally extending inwardly a closing plug for the rear end of the frame and chamber of the barrel, the plug having an induction passage in communication with the induction passages of both spiral flanges, and an eduction passage in communication with the eduction passage of one s iral flange, a

the interior of which the e uction passa e of one spiral flange discharges, substantial y as described.

5. In a pneumatic drill, a hammer frame consisting of a straight central barrel with o positel running s iral flanges encirclin tl fe barre and exten ing from end to end 0 the barrel, the barrel having a central chamber divided into sections, one section to receive a driven stem and another section to receive a driving hammer, and each spiral flange having a spiral induction assage and a spiral eduction passage, with t e eduction passage of one flange terminating at the end of the flange and frame, andthe eduction passage of the other spiral flange terminating in a port laterally extending inwardly, a closing plug for the rear end of the frame and an eduction passage in communication with the eduction passage of one spiral flange, a fluid supply tube connected wlth the closing plug and in communication with the induction passage of the plug, a sup orting tube encircling the fluid suppl the interior of which the GKfllCtlOIi assage of one spiral flange of the hammer frame discharges and a hollow spiral flange, on the exterior of the supporting tube, and into the interior of which the eduction passage of the other spiral flange of the hammer frame discharges, substantially as described.

6. In a neumatic drill, a frame consisting of a straig t central barrel and spiral flanges encircling the barrel and running in opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber'divided into a plurality of sections, providing a section forming a bearing for a driven stem, a section forming an eduction chamber for discharging fluid, a section forming a bearing for a driving hammer, a section forming an induction chamber for fluid to act and recede the hammer, and a section forming a chamber to receive fluid for acting on and driving the hammer, and each spiral flange having an induction assage for fluid in communication with the uid induction chamber of the barrel, and each s iral flange having an eduction passage for uid in communication with the fluid eduction chamber of the barrel, with the eduction passage of one spiral flange terminating at the end of the frame, and with the eduction assage of the other spiral flange terminating m a port laterally and inwardly extending, substantially as described.

7. In a neumatic drill, a frame consisting of a straig t central barrel and spiral flanges encircling the barrel and running in opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber divided into a plurality of sections, providing a section forming a bearing for a driven stem, a section forming an eduction chamber for discharging fluid, a section forming a bearing for a driving hammer, a section forming an induction chamber for fluid to act and recede the hammer, and a section forming a chamber to receive fluid for, acting on and driving the hammer, and each spiral flange having an induction assage forfluid in communication with the uid induction chamber of the'barrel, and each spiral flange having an eduction passage for fluid in communication with the fluid eduction chamber of the barrel, with the eduction passage of one spiralv flange terminating at the end of the frame, and with the eductlon passage of the other spiral flan e terminating in a port laterally and inwar y tu e and into extending, and a closing plug for the rear end of the frame and chamber of the barrel, the plug having aninduction passagein communication with the induction passages of the spiral flanges, and an eduction passage in communication with the eduction passage having the lateral port of the one spiral flange, substantially as described.

8; In a pneumatic drill, a frame consisting of a straight central barrel and spiral flanges encircling thebarrel and running in opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber adapted to receive a driving hammer and provided with an eduction section for discharging fluid and an induction section for. fluid to act and recede and drive forward the hammer, and each spiral flange having an induction passage for fluid in communication with the fluid induction section of the chamber of the barrel, and each spiral flange having an eduction passage for fluid in communication with the fluid eduction section of the chamber of the barrel, with the eduction passage of one spiral flange opening through the rear end of the frame and with the eduction passage of the other spiral flange terminating in a port at the rear end of the frame and laterally and inwardly extending, and a closing plug for the rear end of the frame and chamber of the barrel, the plug having an induction passage in communication with the induction passage of the spiral flanges and an eduction passage in communication with the eduction passage of the spiral flange having the lateral port, substantially as described.

9. In a pneumatic drill, a frame consisting of a straight central barrel and spiral flanges encircling the barrel and running in opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber adapted to receive a driving hammer and provided with an eduction section for discharging fluid and an induction section for fluid to act and recede and drive forward the hammer, and each spiral flange having an induction passage for fluid in communication with the fluid induction section of the chamber of the barrel, and each spiral flange having an eduction passage for fluid in communication with the fluid eduction section of the chamber of the barrel, with the eduction passage of one spiral flange opening through the rear end of the frame and with the eduction passage of the other spiral flange terminating in a port at the rear end of the frame and laterally and inwardly extending, a closing plug for the rear end' of the frame and chamber of the barrel, the plug having an induction passage in communication with the induction passage of the spiral flanges and an eduction passage in communication with the eduction passage of the spiral flange having the lateral port, and a driving rel, su stantially as described.

10. In a pneumatic drill, a frame consisting of a straight central barrel and spiral flanges encircling the barrel and running in opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber adapted to receive a driving hammer and provided with an eduction section for discharging fluid and an induction section for fluid to act and recede and drive forward the hammer, and each s iral flange having an induction passage for uid in communication with the fluid induction section of the chamber of the barrel, and each spiral flange having an eduction passage for fluid in communication with the fluid eduction section of the chamber of the barrel,

with the eduction passage of one spiral flange opening through the rear end of the frame and with the eduction passage of the other spiral flange terminating in a port at the rear end of the frame and laterally and inwardly extending, a closing plug for the rear end of the frame and chamber of the barrel, the

plug having an induction passage in communication with the induction passage of the spiral flanges and an eduction passage in communication with the eduction passage of the spiral flange having the lateral port, a driving hammer operative inthe chamber of the barrel, and a driven stem operative in the chamber of the barrel in advance of the hammer, substantially as described.

11. In a pneumatic drill, a frame consisting of a straight central barrel and spiral flanges encircling the barrel and running in opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber adapted to receive a driving hammer and provided with an eduction section for discharging fluid and an induction section for fluid to act and recede and drive forward the hammer, and each s iral flange having an induction passage or fluid in communication with the fluid induction section of the chamber of the barrel, and each spiral flange having an eduction passage for fluid in communication with the fluid eduction section of the chamber of the barrel, with the eduction passage of one s iralflange opening through the rear end of t e frame and with the eduction passage of the other spiral flange terminating in a port at the rear end of the frame and laterally and inwardly extending, a closin plug for the rear end of the frame and chamber of the barrel, the plug having an induction passage in communication with the induction passage of the spiral flanges and an eduction passage in communication with the eduction passage of the spiral flange having the lateral port, a driving hammer operative in the chamber of the barrel, a driven stem operative in the chamber of the barrel in advance of the hamhammtr operative in the chamber of the bar-- I mer, and a tool head carried by the driven stem, substantially as described.

12. In a pneumatic drill, a frame cons sting of a straight central barrel and sp1r al flanges encircling the barrel and running m opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber adapted't'o receive a driving hammer and provided with an eduction section for discharging fluid and an induction section for fluid to act and recede and drive forward the hammer, and each s iral flange having an induction assage for uid in communication with the uid induction section of the chamber of the barrel, and

each spiral-flange having an eduction ,as-

sage for fluid in communication with the uid eduction section of the chamber of the barrel, with the eduction passage of one s iral flange opening through the rear end 0 the frame and with the eduction passage of the other spiral flan e terminating in a the rear end of the frame and latera ly and inward] extending, a closing plug for the rear encf of the frame and chamber of the barrelf the plug having an induction passage in communication with the induction passage of the spiral flanges and an eduction passage in communication with the eduction passage of the spiral flange having the lateral port, a fluid supply tube connected with the induction passage of the closing 1plu anda su porting tube encircling the uid supply tufle and having on its exterior a hollow spiral flange and receiving into its interior the educted fluid from one spiral flange of the hammer frame and receiving into its hollow spiral flange the educted fluid from the other spiral-flange of the frame, substantially as described. 7

13. In a pneumatic drill, a frame consisting of a strai ht central barrel and spiral ort at flanges encircling the barrel and running in opposite directions on the barrel and extending from' end to end of the barrel, the barrel having a central chamber adapted to receive a driving hammer and provided with an eduction section for discharging fluid and an induction section for fluid to act and recede and drive forward the hammer, and each s iral flange having an induction assage or fluid in commumcation with the g each spiral flange having an eduction sage for fluid in communication with the uid eduction section of the chamber of the barrel, with the eduction passage of one s iral flange opening throughthe rear end 0 the frame and with the eduction passage of the other spiral flange terminating in a ort at the rear end of the frame and latera ly and inwardly extending, a closing plug for the rear end of the frame and chamber of the barrel, the plug havin an induction passage in communication W151 the induction passages uid induc-. tion section of the chamber of the barrel, and

, tube encircling the flui of the spiral flanges and an eduction passage in communication with the eduction passage of the spiral flange having the lateral port, a fluid supply tube connected with the mductionpassage of the closin plug, a sup )orting supply tu e and having on its exterior a hollow s iral flange and receiving into its interior t m educted fluid from one spiral flange of the hammer frame and receiving into its hollow spiral flange the educted fluid fr0m-the other spiral flange of the frame, and a driving hammer operative in the chamber of the barrel, substantially as described.

14. In a pneumatic drill, a frame consisting of a straight central'barrel and spiral flanges encircling the barrel and running in opposite directions on the barrel and extending from end to end of the barrel, the barrel having a central chamber adapted to receive adriving hammer and provided with an eduction section for discharging fluid and an induction section for fluid to act and recede and drive forward the hammer, and each spiral flange having an induction passage for fluid in communication with the fluid induction section of the chamber of the barrel, and each spiral flange having an eduction passage for fluid in communication with the fluid eduction section of the chamber of the barrel, with the eduction passage of one spiral flange opening through the rear end of the frame and with the eduction passage of the other spiral flange terminating in a port at the rear end of the frame and laterally and inwardly extending, a closing plug for the rear end of the frame and chamber of the barrel, the plug having an induction passage in communication with the induction passages of the spiral flanges and an eduction passage in communication with the eduction passage of the spiral flange having the lateral port, a fluid supply tube connected with the induction passage of the closing plug, a su porting tube encircling the fluid supply tu )e and having'on its exterior a hollow spiral sss,1e4

flange and receiving into its interior the educted fluid from one spiral flange ol" the hammer frame and receiving into its hollow spiral flange the educted fluid from the other spiral flange of the frame, a driving hammer operative in the chamber of the barrel, and a driven stem operative in the chamber of the barrel in advance of the driving hammer, substantially as described.

15. In a pneumatic drill, the combination of a hammer frame, consisting of a straight central barrel and spiral flanges 'encircling the barrel and running in up )osite directions on the barrel, each spiral fiange having an eduction passage for fluid, with the eduction passage of one flange terminating at the rear end of the flange, and with the eduction passage of the other flange terminating in a lateral and inwardly extending port, a closing plug having an eduction passage in communication with the port of the eduction passage of the spiral flange, and a supporting tubeeonnected with the rear end of the hammer frame and encircled by a hollow spiral flange, and receiving into its interior the educted fluid from the eduction passage of the closing plug, and receiving into its hollow flange the educted fluid from the other Zpiral flange of the frame, substantially as escribed.

16. In a pneumatic drill, the combination of a frame having on its exterior oppositely running spiral flanges extending from end to end of the frame, a sup orting tube connected with the rear end 0 the frame and encircled by a hollow spiral flange, the spiral flanges of the frame each having an eduction 'assage for fluid, one passage discharging lnto the interior of the supporting tube and the other passage discharging into the passage of the hollow flange, substantially as described.

MARTIN HARDSOCG.

Witnesses:

GRACE HEFLIN, FRED B. HARnsocG. 

